Automatic firearm having electrical ignition of cartridges in a rotating and reciprocating cylinder



April 14, 1970 J. J. DRISCOLL ARM H ING ELECTRICAL IGNITION ROTA'I' AND RECIPROCATING CYL HA I H 0 M 7 M O 1 W A 6 o N d e l 1 F FIG. 6

INVENTOR.

JOHN J. DRISCOLL BY J;

ATTORNEYS April '14, 1970 J. J. DRISCOLL 3,505,927

AUTOMATIC FIREARM HAVING ELECTRICAL IGNITION CARTRIDGES IN A ROTATING AND RECIPROCATING CYLINDER Filed Nov. 6. 1 967 2 Sheets-Sheet 2 FIG. 7

FIG; 8

INVENTOR.

JOHN J. DRISCOLL ATTORNEYS United States Patent Ofiice 3,505,927 Patented Apr. 14, 1970 3,505,927 AUTOMATIC FIREARM HAVING ELECTRICAL IGNITION OF CARTRIDGES IN A ROTATING AND RECIPROCATING CYLINDER John J. Driscoll, Paris, France, assignor to Allied Research Associates, Inc., Concord, Mass., a corporation of Delaware Filed Nov. 6, 1967, Ser. No. 680,935 Int. Cl. F41d 7/00, 9/06, 11/02 U.S. Cl. 89-135 1 Claim ABSTRACT OF THE DISCLOSURE An automatic firearm comprising a cylinder rotatably and reciprocably mounted in a frame and having a plurality of blind cartridge receiving chambers movable between a loading position adjacent a magazine and a firing position in registry with a barrel, in which there is an electrical ignition contact in each cylinder that prepares a firing circuit with a contact on the frame when the cylinder is in firing position.

ing operations, the cost of the metal cartridge case is a n substantial proportion of the cost of the finished cartridge. Further, the mechanism of an automatic weapon using metal cased cartridges is inherently complex. The cartridge must be taken from a magazine, loaded into the breech, and then locked there. For that purpose, a breech bolt or block must be provided. A breech locking system is also necessary, to delay the opening the breech after firing while the internal pressure of the powder in the cartridge is still relatively high and dangerous. After firing, the spent cartridge case must be extracted and ejected from the chamber before another cartridge can be inserted.

It has been proposed prior to my invention to eliminate some of the problems associated with a metal cartridge by the use of a consumable cartridge case. However, the breech closing and locking problems still remain, and if no extraction mechanism is provided in an otherwise conventional weapon a misfire will put it out of action until it can be completely disassembled.

The principal objects of my invention are to simplify the construction of single-shot, repeating, and automatic firearms and to eliminate the need for metal cartridge cases in such weapons. Briefly, these and other objects of my invention are attained by the use of a novel cartridge having a consumable case and a primer, well-insulated from the heat of the chamber, located within the case and against the base of the projectile. The primer may be designed for electrical, mechanical, or a combination of both methods of ignition. I further provide a weapon comprising one or more blind chambers each adapted to receive one of the cartridges of my invention, case first. Apparatus is provided for successively moving the chamber into operative relationship with a barrel, and for loading an empty chamber after a round in it has been fired. Preferably, the apparatus is arranged to carry each empty chamber away from the barrel into a position which would assist cooling and from which the cartridge may be extracted if necessary if a misfire has occurred.

The electrical embodiment of the apparatus includes an electrical contact adapted to engage a contact connected with the catridge in the chamber in position to be fired. As will appear, the gun is adapted to be either hand cocked, or automatically cocked, in dependence on the position of a trigger controlling a switch that activates the firing circuit when depressed. Recoil is employed to advance the next chamber into firing position and load another cartridge from the magazine into the cartridge carrier. As there is no residue in the chamber after firing, clearing and extraction are unnecessary. The mechanism may be quite simple, with few moving parts, as several conventional components are unnecessary; as, for example, the breech block, breech lock, firing pin and spring, extractor, ejector, etc., and the weapon and its ammunition can consequently be made light and compact and easy to produce and maintain.

The manner in which the improved firearms and ammunition of my invention may be constructed and used will best be understood in the light of the following detailed description, together with the accompanying drawings, of various embodiments thereof.

In the drawings,

FIG. 1 is a schematic elevation of an electrically operated automatic firearm in accordance with a preferred embodiment of my invention, with parts shown in crosssection and parts broken away;

FIG. 2 is a schematic wiring and mechanical diagram of the ignition mechanism for the apparatus of FIG. 1, with parts shown in cross-section and parts broken away;

FIG. 3 is an elevational view of a cylinder forming part of the apparatus of FIG. 1, taken essentially along the lines 3-3 in FIG. 1;

FIG. 4 is a diagrammatic sketch of part of a cartridge shown in FIG. 2;

FIG. 5 is a side view of the cylinder shown in FIG. 3;

FIG. 6 is a schematic diagram of a modification of the apparatus of FIGS. 1 through 5;

FIG. 7 is a fragmentary elevational cross-sectional view of another modification of the apparatus of FIG. l-5;

FIG. 8 is an end view, with parts shown in cross-section and parts broken away, of a projectile and primer assembly in accordance with a modification of my invention, taken essentially along the lines 8-8 in FIG. 9;

FIG. 9 is an elevational view in cross-section of the apparatus of FIG. 8, taken essentially along the lines 99 in FIG. 8;

FIG. 10 is an end view of a projectile and primer assembly in accordance with another modification of my invention; and

FIG. 11 is an elevational view in cross-section of the apparatus of FIG. 10, taken essentially along the lines 1111 in FIG. 10.

As will be apparent to those skilled in the art, many portions of the automatic weapon of my invention may be of a conventional nature. For example, the chamber is readily adaptable to most conventional magazine systems including tubular or boX feeds, a rotary magazine or a belt-feed system. Therefore, I have only illustrated those modifications of conventional practice that are necessary to exhibit the invention in its intended environment. Specifically, referring to FIG. 1, the firearm has a frame 1 that may extend as suggested at 2 to form a conventional tang, and may be provided at its lower side with a trigger guard 3 housing a trigger 4. A conventional barrel 5 threadedly engages the frame as indicated at 6. Although that feature is not illustrated in the drawings, the frame may obviously be divided at convenient places for assembly and disassembly and the parts secured together by screws, bolts or the like.

a primer forming a The frame 1 is recessed as indicated at 7 to allow eciprocation of a cartridge carrier comprising a cylinder i provided with four chambers 9 disposed symmetrically tbout its periphery. The cylinder 8 is mounted for sliding lIld rotation on a central shaft 10 for movement between he position shown and a position to the left of that lhOWIl. In the latter position, a return spring 11 is com- )ressed between the cylinder and frame to drive the cylinler back to the position, shown. Preferably, the chambers 9 terminate in projected tapering portions 12 each adapted to engage a cooperating recess at the entry of the barrel 5 to provide a gas seal between cylinder and barrel when a round is fired.

On the cylinder 8 are formed a set of cam grooves 13 (see also FIG. 5) adapted to engage a cam follower 14 on the frame. By that arrangement, each time the cylinder 8 moves backwardly, the cylinder is caused to rotate 90 degrees and bring the next chamber 9' into firing position. It will be apparent that the straight portions of the grooves 13 and projections 12 serve to guide the cylinder into accurate alignment with the barrel. Additional guides could be provided for this purpose on the frame and cylinder, if so desired, to be engaged when the cylinder nears its forward position.

A magazine 15, of any conventional construction is provided to supply cartridges such as 16 under the control of a loading mechanism next to be described. As shown, above the magazine is a passage 17 in which a plunger 18 is reciprocally mounted. The plunger 18 may be urged into the position shown by conventional means such as a spring 19.

The plunger 18 moves together with and in opposition to the cylinder 8. Various conventional mechanisms could be employed for this purpose, but as here schematically indicated, there may be provided a flange 20 on the cylinder 8 to engage a follower on an arm 21. The arm 21 is connected to a rack 22 that is coupled to a rack 23 attached to the plunger 18 through a pinion 24 journalled in the frame. By that arrangement the plunger 18 will be pulled back out of the path of the uppermost cartridge 16 and allow that cartridge to come up into position when the cylinder 8 is in its rear position. When the cylinder 8 comes forward, the plunger 18 drives the cartridge 16 into the chamber 9 that is then in position, and holds the succeeding rounds in the position shown in FIG. 1.

It will be apparent that by the arrangement just described, when a round is fired in the chamber 9 that is in communication with the barrel 5, the recoil will drive the cylinder 8 backwards to compress the spring 11, and also to withdraw the plunger 18 and allow a new round to feed up from the magazine. On the return stroke, a new round will be driven into the lower chamber 9 by the plunger 18, and a live round will go into firing position.

As the cylinder and barrel come into registration, a pair of contacts are engaged; if the trigger is then depressed, the next round will be fired. The ignition apparatus will next be described in more detail in connection with FIG. 2.

The metal frame 1 is employed as a reference terminal for the electric firing circuit, and all metal parts of the firearm may be considered to be at this potential. Referring to FIG. 2, the preferred construction of each cartridge 16 is such that its metal projectile 25, of lead, lead alloy or the like, engages a cylindrical portion 26 of the chamber 9 firmly, and thus establishes electrical contact with the frame. The rear portion 27 of each cartridge 16 comprises an outer insulating jacket 28 of explosive, electrically insulating material, such as a conventional plastic explosive material selected to have a high mechanical stability but to burn completely when a central charge 29 is ignited by a primer 30. Preferably, at least the rear portion 27 of the cartridge and the rear portion of each chambet 9 should be tapered somewhat as shown, so that the cartridges 16 may be readily loaded without the problems that might otherwise be caused by slight misalignment or by air trapped in the chamber.

As shown in FIGS. 2 and 4, the primer 30 is electrically connected to an outer rim 31 of light metal, such as aluminum foil or the like. The primer may be of any con ventional electrically fired type. For example, the primer may be a 0.002 inch diameter platinum-iridium bridge wire in a charge of lead styphnate.

The return path for the electrical element of the primer is through the bullet 25 to the frame 1. The outer contact ring 31 is insulated from the bullet by the jacket 28.

When a cartridge 16 is firmly seated in the chamber 9, the ring 31 is in electrical contact with a metal ring 33 mounted in the wall of the chamber and separated from the surrounding metal by suitable insulating means indicated at 34. The ring 33 is electrically connected to an outer contact 35. One such contact 35 is provided for each of the chambers 9.

When one of the chambers 9 is in firing position and in registry with the barrel 5, its contact 35 engages a contact 36 mounted in insulated relation in the frame 1 by suitable insulating means 37. A wire 38 provided with conventional insulation is led through suitable assages in the frame to a terminal 40 of a conventional three-position switch 41 that is preferably mounted on the tang of the weapon in the position of a conventional safety. In the position of the switch shown, the presence of a round in firing position makes no difference, as there is no electrical circuit to the contacts 35 and 36. When the armature of the switch engages the terminal 40, a circuit is completed through a battery 42 to a contact 43 mounted adjacent a projection on the trigger 4.

As indicated, the trigger 4 is pivoted to the frame at 44 and urged into the position shown by a conventional spring 45 seated in the frame. When the trigger 4 is pressed, the contact 43 engages a cooperating portion 44 of the frame to complete an electrical circuit and fire the round then in firing position.

As long as the trigger 4 is kept depressed and the switch 41 is in the automatic position, each round as it fires will cause the cylinder 8 to recoil and load another round, and as soon as the next round is brought into alignment with the barrel, it will be fired and the process will be repeated. The process can be interrupted at any time by either releasing the switch 4 or by moving the switch 41 to its safe position.

If desired, the switch 41 may be provided with a third manual position intermediate the safe and automatic positions. To provide for single shot operation, the intermediate terminal of the switch is connected to the terminal 40 through a resistor 47 in parallel with a capacitor 48. With the switch in this position and the trigger depressed, one pulse of current will flow to fire one round, but the next round will not be fired unless the trigger is again released and depressed to allow the capacitor 48 to discharge. The resistor should be large enough so that the current through it will not cause firing.

While I have described the firearm of FIGS. 1 through 5 as being of the simple blow-back variety, it will be apparent to those skilled in the art that if desired either a conventional gas or recoil operated locking locking mechanism could be connected between the cylinder and the frame to delay recoil and thereby permit higher pressures to build up in the barrel and chamber to produce a higher muzzle velocity. Various possible modifications of this kind are known to those skilled in the art, however. And, since the details of such modifications form no part of my invention, they will not be described. I

The apparatus of FIGS. 1 through 5 is prepared for firing by inserting a loaded magazine 15 and reciprocating the cylinder 8 back and forth manually until a live round is in position. It can then be fired simply by pressing the trigger in the manner described above. In the event of a misfire, the cylinder 8 can again be reciprocated manually, to bring the bad round outside of the frame where it can be extracted with a pointed, pincer-action, or suctionoperated, tool. Alternatively, a portion of the projectile 25 can be made of iron, and a magnetic or an electromagnetic extractor can be provided to be actuated by a suitable switch when it is desired to extract a defective round.

While I have illustrated and described the revolving mechanism as the preferred embodiment of my invention, FIG. 6 illustrates a modification which could be employed, if so desired. As indicated in FIG. 6, a cartridge carrier 50 is provided with two chambers, 51 and 52, cooperating with a barrel 53 and two magazines 54 and 55 on each side of the barrel. In the position shown, a round in the chamber 51 is in registry with the barrel53, and a round in the chamber 51 can at that time be discharged by contacts such as contacts 35 and 36 in FIG. 2 in combination with a circuit of the kind described above. When one of the chambers 51 and 52 is in firing position, the other is in position to receive a new cartridge from the associated single or dual magazines 54 or 55.

The cartridge carrier 50 may be caused to oscillate back and forth between the firing positions of the two chambers by various arrangements. For example, as shown, the cartridge carrier may be pivotally secured to a block 56 as indicated at 57. The block 56 may be fixed to the barrel 53, so that the cartridge carrier 50 and the barrel move together on recoil.

A pair of earns 58 and 59, mounted in opposed relationship on a shaft 60 journalled in the block 56, control the position of the cartridge carrier 50. A gear 61 rotatable on the shaft 60 and connected thereto through a oneway clutch as indicated by the pawl 62 is driven during recoil by a rack 63 on the frame to rotate a different one of the earns 58 and 59 into engagement with the carrier 50 each time a round is fired. A pair of stops 64 on the frame limit the movement of the carrier.

FIG. 7 illustrates a modification in which the cylinder 65 and barrel 66 are arranged to reciprocate together upon firing, with respect to the frame, not shown. For that purpose, a lug 67 formed on the barrel 66 slida-bly engages a flange 68 on the cylinder 65. The flange 68 also serves to actuate the magazine as described in connection with FIG. 1.

In the apparatus of FIG. 7, each chamber in the cylinder is bored to receive a sliding sleeve 69. When a round is fired, the projectile carries the sleeve 69 into a recess 70 in the barrel to form a gas seal. The sleeve is then returned to the cylinder by any suitable means, here shown as a pin 71 slidable in a slot 72 in the barrel and urged to the left in FIG. 7 by a spring 73. During the loading of a round, as suggested in the lower part of FIG. 7, the sleeve 69 will be held in place as the cartridge 16 is moved into the chamber.

The modification of FIG. 7 may be arranged for elec trical ignition in the manner described in connection with the embodiment of FIG. 1, by the installation of an electrical contact assembly 33, 34, 35 in FIG. 1 in appropriate passages 74 in the cylinder 65 of FIG. 7. Alternatively, mechanical ignition may be provided for by the installation of firing pin assembiles in each of the passages 74.

FIGS. 8 and 9 show a projectile generally designated 75 and including an ignition assembly adapted to be either mechanically or electrically actuated. The projectile 75 comprises a main metal body portion 76 of any desired ballistic configuration, formed at the rear with a central recess 77 in which a primer 78 is installed, the primer being provided with a pair of terminals between which a bridge wire for electrical ignition is connected, and provided with a charge that can also be detonated by percussion. Disposed in a suitable recess in the body portion 76 is a striker disk 79 of a harder metal than the body portion. The striker disk and the portion of the primer in electrical contact with one of its terminals, is insulated from the body portion by suitable insulating means indicated at 82. The second terminal of the primer is in elec trical contact with the body portion 76.

The striker disk 79 is provided with a number of inwardly projecting striker arms 80. A sufiicient number, preferably at least four, of such arms is provided that when the disk 79 is struck anywhere on the periphery by a firing pin 81, the disk will be distorted and one of the arms 80 will strike the primer 78, causing the primer to detonate. Alternatively, the primer can be electrically actuated as described above.

A consumable cartridge case, of the type described above, is secured to the projectile in any conventional manner. The case may comprise the sole propellant charge, or may contain a supplementary charge of conventional propellant. With either construction, ignition of the propellant is caused by the burning gases expelled from the aperture 77 when the primer is struck.

If desired, the striker disk 79 may be made of a relatively ductile material, such as copper or the like, and shaped to be extruded when the round is fired. By that arrangement, the disk may serve as a gas seal, or act as a rotating band engaging the rifling.

For use in either electrically or mechanically actuated weapons, the contact ring 31 of FIG. 4 may be modified by the addition of a plurality of projections such as in FIG. 8, rather than the single connecting strip required for an electrical connection. The function of the contacting portion 30 in FIG. 1 may be performed by the ends of such projections, in both mechanical and electrical contact with the primer. By that arrangement, the round 16 can be fired either electrically, as described, or by striking the ring 31 to deform it and detonate the primer in the manner described in connection with the apparatus of FIGS. 8 and 9.

FIGS. 10 and 11 show another modification of the projectile and priming assembly of a mechanically ignited cartridge. As in the embodiment of FIGS. 8 and 9, the projectile comprises a body portion 82 of cast metal. A rotating band 83, of a harder metal, is disposed in a groove around the periphery of the body portion. Between the rotating band 83 and the projectile body is disposed an annular ring 84 of a percussion ignited priming composition.

The priming ring 84 communicates with the rear of the projectile body 82, and thence with the charge in the consumable cartridge case, through a number of passages 85. When the rotating band 83 is struck by a firing pin, the primer 84 will ignite and expel burning gases through the passages 85 to ignite the propellant charge.

While I have described my invention with respect to the details of particular embodiments thereof, many changes and variations will occur to those skilled in the art upon reading my description, and such can obviously be made without departing from the scope of my invention.

Having thus described my invention, what I claim is:

'1. An automatic firearm, comprising a frame, a cylinder mounted for reciprocation and rotation along and about a predetermined axis in said frame, means resiliently urging said cylinder toward a first position on said axis, a plurality of cartridge carrying chambers in said cylinder each having a closed end and an open end adapted to receive a cartridge, a barrel mounted on said frame in registry with one of said chambers when said cylinder is in said first position, a cartridge magazine mounted on said frame in registry with another of said chambers, means responsive to recoil of said cylinder for rotating the cylinder to place another chamber in registry with said barrel and simultaneously place another chamber in registry with said magazine, means responsive to reciprocation of said cylinder to load a cartridge from said magazine into each chamber coming into registry with the magazine, an electrical inner contact in each chamber, insulated from the walls of the chamber, and connected to an insulated outer contact outside the chamber, a firing contact on said frame, insulated from the frame, and 509,091 11/1893 McCullough 4260 adapted to contact the outer contact for a chamber in 944,448 12/1909 Lefever 89-157X registry with the barrel, and an electrical circuit including 946,351 1/ 1910 Haeghen 89-156 a source of current and a manually operable switch and 1,332,060 2/1920 Pacilli 89-135 X extending between said frame and said firing contact to 5 2,790,353 4/1957 Bird 89-155 supply voltage between the frame and the inner contact 2,876,680 3/ 1959 Meyer et a1. 89156 of a chamber in registry with the barrel when the switch 3,299,812 1/ 1967 Suh et a1 8928 is closed.

Referen es Cited BENJAMIN A. BORCHELT, Primary Examiner UNITED STATES PATENTS 10 S. C. BENTLEY, Assistant Examiner 11,197 6/1854 Lindner 4260 38,350 4/1863 Whitcomb s9 2s 156 44,363 9/1864 Wood 42-61 

